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F. W. JENKINS. GOMPOUND ENGINE.

Patented Dec. 16, 1884.

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FRANK W. JENKINS, OF BROOKLYN, NEV YORK, ASSIGNOR TO DAUPHIN S. EINES, OF SAME PLAGE, WILLIAM A. PERRY, OF BAY RIDGE, NEY YORK, AND CHARLES O. VORTHINGTON, OF IRVINGTON, NEV YORK.

COMPOUND ENGINE.

SPECIFICATION forming part of Letters Patent No. 309,228, dated December 16, 188%.

Application filed February 29, 1884.

To @ZZ whom, it may concern,.-

Be it known that I, FRANK W. JENKINS, a citizen of the United States, residing in the city of Brooklyn, county of' Kings and State 5 of New York, have invented certain new and useful Improvements in Compound Engines, fully described and represented in the following specication andthe accompanying drawings, forming a part of the same.

This invention relates to that class of engines which consist of a cylinder into which the steam is admitted direct from the generator, and a second cylinder of larger size, into which the steam passes from the exhaust of the i 5 iirst cylinder, and in which it acts expansively, Y

and which are classed in the art under the general title of Compound Engines.7 The engines of this class possess many advantages and have gone into very extensive use, par- 20 ticularly for pumping and other like purposes where it is desirable that the piston-rod of the engine should act directly upon the load. The especial adaptation of this class of engines for such uses is due to the fact that by them 2 5 the economy due to the use of the steam expansively is secured, and at lthe same time a' practically uniform propulsive power is 1n aintained throughout the entire stroke of the engine without the aid of a ilywheel or other 3o heavy moving part. In order to secure themost economical results with an engine of this class it is desirable that the size of the engine should be so graduated'with relation to the work to be performed that when operating 3 5 under its ordinary running conditions the full power of the engine will be but little in cxcess of the resistance offered by the constant load. It frequently happens, however, in running these engines that for various reasons 4o it is desirable that the engine should be able to temporarily perform an amount of labor considerably in excess of that which it is ordinarily called upon to perform, and consequently it is highly desirable that the engine 4 5 should be capacitated to meet these temporary demands, even though to do it the steam must be temporarily used in anuneconomical manner.

It is the object of the present invention to (No model.)

provide means by which this result is accom- 5o plished; and to that end the invention consists in providing the steam chest of the smaller cylinder with connections by which the steam admitted t0 said chest from the boiler may, when desired, be allowed to pass directly to 5 5 the steam-chest of the larger cylindenso as to act upon the piston of said larger cylinder at its initial or boiler pressure throughout its entire stroke, instead of expansively and at a reduced initial pressure. It will readily be 6o seen that when the steam is thus admitted to the larger cylinder at its initial or boiler pressure the pressure of the steam upon both sides ofthe piston of the smaller cylinder will be equal, so that said smaller piston will be 65 constantly held iu equilibrium, and will consequent-ly perform no work; but it will also be observed that the relative areas of the smaller and larger pistons are such that the increased pressure thus applied to the larger 7o piston will very much more than compensate for the loss of the smaller piston, so that when the engine is operating in this manner it will develop a much greater power than when op erating in the ordinary manner, although to 7 5 develop this increased power it will sacrifice the economy due to the use of the steam expansively.

In the accompanying drawings,Figure lis a plan view, partially in section, of an ordinary Se duplex compound engine embodying the invention. Fig. 2 is an' end elevation,partly in section, of the same, looking from the left of' Fig. l, and Fig. 8 is a similar view illustrating a modification to be hereinafter referred 8 5 to.

Referring to said dra-wings, it is to be understood that the engine therein shown consists of two cylinders, l() 1l, which receive steam direct from the boiler, and in which the 9o steam acts at its full pressure throughout the whole or nearly the whole stroke of the piston, and two larger cylinders, 12 13, into which the steam passes from the exhaust of the first cylinders, and in which it acts expansively, 95 after which it is exhausted into a condenser or into the open air, the whole forming an ordinary duplex compound engine. The cylinders l0. 11 are provided with the usual steamchests, 14 15, into which the steam is admitted through the pipe 16 direct from the boiler, and the cylinders 12 13 are also provided with similar steamchests, 17 18, which are connected by pipes 19 2() with the exhaust-ports ofthe rst cylinders, the exhaust-ports of these last cylinders being provided with a pipe, 21, leading to a condenser or to the open air. 'The several cylinders are provided with induction and exhaust ports 7 8 9, of the usual construction, which are controlled by valves 6 of the common form, the rods 22 23 of which are provided with the usual connections by which the valves of each side of the engineV are operated by the main piston-rod of the opposite side, as in the well-known Worthington Duplex Pumping-Engine.7

In order to permit the steam to passdirectly from the boiler to the cylinders 12 13 when Yit is desired tov temporarily increase the capacity of .the engine as before explained the steam-chests 14A 15 are provided with openings 5, which communicate through pipes 24 with like openings, 4, in the walls of the ex-l haust-ports 9 of the cylinders 10 11, as shown in Figs. 1 and 2. The pipes 24 are provided with ordinary throttle valves or cocks, 25, by which said pipes can be opened or closed, so as to establish or shut oft' communication between the chests 14 15 and the ports 9, as may be desired.

AThe operation of the-engine thus organized is asfollows: If the engine is to perform only the Ordinary labor for which it is intended, the valves or cocks 25 will be closed, so as to shut off communication through the pipes 24. The throttle-valve of the pipeV 16 being then opened, the steam-will pass from the boiler to the steam-chests 14 15, and will enter the cylinders 10 11, in which cylinders it will act at the full boiler-pressure throughout thewhole or nearly the whole stroke of the pistons, after which, as the pistons in said cylinders commence their return stroke, the steam already in the cylinders will pass through the pipes 19 20 and enter the steam-chests 17 18,

from which it will pass to the cylinders 1213,

where it will act expansively upon the pistons of said cylinders, so asto aid the steam which is at the same time admitted directly from the boiler to the correspondingI sides of the pistons of the cylinders 10 11, and so the operation is repeated, the steam which enters lthe cylinderslO 11 at each stroke being exhausted into the steam-chests 17 18, so as to act expansively in the cylinders 12 13 at the next stroke. After acting expansively i-n the cylinders 12 13 the steam is exhausted through the pipes V12.13 maybe variedV from that shown in the drawings, theproportions thereA shown being only an approximation of the true proportions for the purpose of illustrating the princ iple and operation of the invention. These cylinders will, however, vbe so proportioned that the steam acting upon the pistons of the i two cylinders as just described will exert a substantially uniform propulsive power throughoutthe entire stroke of the engine, and in-order to secure the greatest economy inthe use of the steam the pistons of the cylinders 12 13 will be of at least two and onehalf times the area of the pistons of the cylinders 10 11. From this it will be seen that -if lthe steam is allowed to enter the larger cylinders at its full or boiler pressure these cylinders alone will develop a much greater power thana'll four of the cylinders Will develop when acting in the regular way, as already described, although in doing it the economy of using the steam expansively will be sacrificed. Vhenever, therefore, it becomes desirable for any reason to temporarily increase the capacity of the engine, the throttlelvalves or cocks 25 are opened, so 'that the steam will pass directly from the chests 14V 15 through the pipes 24 to the exhaustports 9 of the cylinders 10 11, and thence through the pipes 19 20 to the steam-chests 17A 18, thus causing the steam to be supplied at its full or boiler pressure to both the cylinders 10 11 and 12 13. W'hen this is-,done, the pressure upon both sides of the pistons of the cylinders 10 11 will, of course, be the same, so that said pistons will always be in equilibrium, and will consequently develop no power; but the increased pressure upon the larger pistons of the cylinders 12 13 will very much more than compensate for this, and thus have the effect of actually increasing the power ofthe engine. It is not necessary in order to accomplish this result that the pipes 24 should communicate with Ythe exhaustports 9 of the cylinders 10 11, as these pipes may, if preferred, be arranged, as shown lin Fig. 3, so as to communicate directly with the pipes 19 20, instead of communicating with said pipes through the exhaust-ports 9.

Although the invention is herein shown as applied to a duplex engine, it is to be understood that it is not limited in its application to this class of engines, as it may be applied with equally good resultsto single compound engines.

What I claim, therefore, is

1. The combination, with two cylinders arranged to form a compound engine and provided with a pipe for conducting the steam from the exhaust-port of the first cylinder to the steam-chest of the second cylinder, of a pipe arranged to establish communication between the steam-chest of the iirst cylinder and said conducting-pipe,and a cock or valve, 25, for closing said communication, substantially as described.

IOO

2. The combination, with two cylinders ar- `25,1"or closing said communication, substan- 1o ranged to form a compound engine and protially as described. vided with a pipe for conducting the steam In testimony whereof I have hereunto set from the exhaust-port of the rst cylinder to l my hand in the presence of two subscribing 5 the steam-chest of the second cylinder, of a witnesses.

pipe arranged to establish communication between the steam-chest of the first cylinder and said conducting-pipe through the exhaust port of seid first cylinder, and n cook or Valve, l

FRANK XV. JENKINS. "Witnesses:

T. H. PALMER, GEO. H. GRAHAM. 

